A process for operating an anesthesia apparatus or respirator with a breathing circuit is disclosed in DE 199 58 532 C1, where the speed of the gas delivery element is changed to set the respiration.
Inhalation anesthesia can be initiated for a patient so far only in a time-consuming manner and with incomplete monitoring. It is necessary to operate with a high fresh gas flow for a relatively long time in case of a half-closed rebreathing system. This is in order to exchange the gases in the breathing system corresponding to the desired concentration and as a function of the volume of the breathing circuit and the patient's parameters.
Even though a desired rapid initiation of anesthesia is guaranteed in case of direct feed of the fresh gas, which fresh gas contains O2 and N2O, enriched with a volatile anesthetic, with a half-open system with a separate fresh gas outlet, it is disadvantageous that the monitoring of the pressure and the gas concentration is not ensured. A technical safety system is difficult to embody. Moreover, the patient must be disconnected and connected to the circulation system after the initiation of the anesthesia.